Properties of Polymethyl Methacrylate (PMMA)
Polymethyl methacrylate (PMMA) is a transparent thermoplastic known for its outstanding optical clarity and rigidity. Commonly used as a lightweight and shatter-resistant alternative to glass, PMMA is widely applied in products like lenses, light diffusers, and acrylic panels.
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The following table provides a comprehensive list of polymethyl methacrylate (PMMA) properties in both SI and US customary/Imperial units at normal temperature and pressure (NTP).
Click on the button to switch between Metric and Imperial units.
| Physical Properties | Metric |
|---|---|
| Category | Thermoplastic |
| Density | 1180 - 1190 kg/m3 |
| Water Absorption | 0.2 - 0.3 %wt/day |
| Mechanical Properties | Metric |
| Ultimate Tensile Strength | 72 MPa |
| Yield Tensile Strength | 54 - 73 MPa |
| Ultimate Compressive Strength | 72 - 124 MPa |
| Young’s Modulus (E) | 3.036 GPa |
| Flexural Modulus | 2.24 - 3.17 GPa |
| Elongation at Break | 2.5 - 4% |
| Rockwell Hardness (M) | 92 - 100 |
| Thermal Properties | Metric |
| Melting Point | 45 °C |
| Thermal Conductivity | 0.17 - 0.19 W/m·K |
| Specific Heat Capacity (Cp) | 1450 J/kg·K |
| Coefficient of Thermal Expansion (αL) | 3.4×10-5 - 7.7×10-5 1/°C |
| Glass Transition Temperature (Tg) | 105 °C |
| Electrical Properties | Metric |
| Relative Permittivity (@1 MHz) (εr) | 2.76 |
| Electrical Resistivity | 1015 Ω·cm |
| Dielectric Field Strength (Ed) | 150 kV/cm |
| Optical Properties | Metric |
| Refractive Index (589 nm) | 1.49 |
| Transmittance | 92% |
| Hazardous Data | Metric |
| Flammability Rating (ANSI/UL 94) | HB |
Unless stated otherwise, all values are taken at room temperature (approximately 20°C or 68°F) and 1 atm pressure. (1 atm = 101,325 Pa)
References: 1) Cardarelli, François. Materials Handbook: A Concise Desktop Reference. Switzerland: Springer International Publishing, 2018. 2) CRC Handbook of Chemistry and Physics, 97th Edition. United Kingdom: CRC Press, 2016-2017. 3) A.M. Howatson, P.G. Lun, J.D. Todd, P.D. Engineering Tables and Data. United Kingdom: University of Oxford, Department of Engineering Science, 2009.